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81.
总结了70例重症脑挫伤行气管切开术后,可出现的相关问题,采取相应的护理措施.重点加强人工道气管导管护理,气道湿化、吸痰护理、气管切口护理等,减少气管切开的并发症,降抵重症脑患者死亡率.参6.  相似文献   
82.
药物及个人护理品(PPCPs)在地表水中的污染问题已引起了广泛关注,人工湿地(constructed wetlands,CWs)在PPCPs去除中具有突出优势,然而关于不同类型PPCPs在CWs去除中的相互作用研究得还较少.本研究选取两种常用且相对分子质量接近的典型PPCPs——广谱抗菌剂三氯生(TCS)和非甾体抗炎药物双氯芬酸(DCF)作为目标污染物,分析其在潜流人工湿地中的去除行为,并探讨不同季节和不同进水条件(TCS、DCF单独投加和二者复合投加)对两种污染物去除效果的影响.人工湿地系统的主要参数如下:上行流式潜流人工湿地,水力负荷为0.20 m·d-1,水力停留时间为3 d,进水方式采用连续流进水.PPCPs初始进水浓度为TCS 80 μg·L-1和DCF 25 μg·L-1.结果表明,TCS和DCF在夏季平均去除率(分别为91.72%和85.86%)均显著高于冬季(分别为52.88%和32.47%).独立样本t检验证实,不同进水条件(TCS、DCF两者单独投加和二者复合投加)下,TCS和DCF的去除效果无显著差异.同时,TCS和DCF的降解产物在不同进水系统中没有差异,其中TCS在不同系统中均未检测到代表性降解产物,DCF在不同系统中主要降解产物均为3,5-二氯苯甲酸和间二氯苯,两种典型PPCPs在微量(μg·L-1)层级上无显著拮抗、竞争等相互作用.  相似文献   
83.
After closure, municipal solid waste (MSW) landfills must be managed and controlled to avoid adverse effects on human health and the environment (HHE). Aftercare (or post-closure care) can be brought to an end when the authorities consider the landfill to no longer pose a threat to HHE. Different approaches have been suggested for long-term landfill management and evaluation of aftercare completion. In this paper, research on aftercare and its completion is analyzed and regulatory approaches for the completion of landfill aftercare are reviewed. Approaches to aftercare could be categorized as (i) target values, (ii) impact/risk assessment, and (iii) performance based. Comparison of these approaches illustrates that each has limitations and strengths. While target values are typically used as screening indicators to be complemented with site-specific assessments, impact/risk assessment approaches address the core issue about aftercare completion, but face large uncertainties and require a high level of expertise. A performance-based approach allows for the combination of target values and impact/risk assessments in a consistent evaluation framework with the aim of sequentially reducing aftercare intensity and, ultimately, leading to the completion of aftercare. At a regulatory level, simple qualitative criteria are typically used as the primary basis for defining completion of aftercare, most likely due to the complexity of developing rigorous evaluation methodologies. This paper argues that development of transparent and consistent regulatory procedures represents the basis for defining the desired state of a landfill at the end of aftercare and for reducing uncertainty about the intensity and duration of aftercare. In this context, recently presented technical guidelines and the ongoing debate with respect to their regulatory acceptance are a valuable step towards developing strategies for the cost-effective protection of HHE at closed MSW landfills. To assess the practicality of evaluation methodologies for aftercare, well-documented case studies including regulatory review and acceptance are needed.  相似文献   
84.
Pharmaceutical and personal care products (PPCPs) and corresponding transformation products have caused widespread concern due to their persistent emissions and potential toxicity. They have wide octanol-water partition coefficients (Kow) and different ionization constants (pKa) resulting in a poor analysis accuracy and efficiency. A suitable analytical method is the first prerequisite for further research on their environmental behavior to prioritize the substances. This study reviewed a full-scale analytical protocol for environmental samples in the recent ten years: from sampling to instrumental methods. Passive sampling techniques were compared and recommended for long-term continuous and scientific observation. A quick and effective sample extraction and clean-up method are highly required. Chromatographic methods coupled to mass spectrometry for determining PPCPs with a wide range of logKow (?7.53 to 10.80) were summed up. High-resolution mass spectrometry was confirmed to be a promising strategy for screening unknown transformation products, which would provide a nanogram level of detection limits and more accurate mass resolution. Screening strategies and mass change principles were summarized in detail. The recovery rate was important in multiple contaminants analysis identification and factors affecting the recovery rate of PPCPs were also discussed in this review, including sample matrix, target compounds characteristics, extraction method and solid-phase adsorbent. This review provides useful information for the selection of appropriate analytical methods and future development directions.  相似文献   
85.
药物和个人护理品(PPCPs)是一类新污染物,对水生生物具有潜在危害.为探究宁夏入黄排水沟中PPCPs的污染特征与生态风险,利用固相萃取-超高效液相色谱-质谱联用仪对21种PPCPs进行检测分析.结果表明,宁夏入黄排水沟中目标PPCPs的总浓度范围在47.52~1 700.96 ng·L-1之间.其中,环丙沙星、对乙酰氨基酚、二苯甲酮-3和避蚊胺的检出率大于80%;检出浓度最大的5种化合物分别为对乙酰氨基酚、避蚊胺、咖啡因、二苯甲酮-3和左氧氟沙星,浓度最大值分别为597.21、563.23、559.00、477.28和473.07 ng·L-1.空间分布上,排水沟中PPCPs的污染程度呈现出银川市>石嘴山市>吴忠市>中卫市的分布特征,入黄口采样点PPCPs总浓度范围为124.82~1 046.61 ng·L-1.来源分析表明,宁夏入黄排水沟中磺胺嘧啶和土霉素主要来自于畜禽养殖,左氧氟沙星和环丙沙星主要来源于医疗废水,三氯卡班和三氯生来自于生活污水和工业废水,咖啡因和避蚊胺主要来自于生活污水.入黄排水沟中双氯芬酸、西咪替丁、三氯卡班和三氯生的污染程度与区域人口数量和经济发展水平呈正相关.生态风险评价结果显示,宁夏入黄排水沟中左氧氟沙星、双氯芬酸、吉非罗齐、二苯甲酮-3和三氯卡班表现为高风险;值得关注的是,大多数采样点PPCPs的综合生态风险表现为高风险.  相似文献   
86.
Knowledge of the investment rules adopted by breeders and non-breeders, and the factors that affect them, is essential to understanding cooperative breeding as part of a life-history tactic. Although the factors that affect relative contributions to care of young have been studied in some cooperative bird species, there is little data on mammals, making coherent generalisations within mammals and across taxa difficult. In this study, we investigate individual contributions to pup escorting, a strong predictor of offspring provisioning, in the banded mongoose (Mungos mungo), a cooperatively breeding mammal in which reproductive skew is low. Contributions by those under a year old (which virtually never breed) increased with age and body weight but were generally low. Among older age classes (yearlings and adults), individuals that had not bred in the current litter generally contributed less to escorting than those that had bred (with the exception of yearling males). In addition, females that did not breed reduced their investment if they were heavy presumably because such females are more likely to breed in the following event and benefit from saving resources for this. The generally greater contributions by breeders in banded mongooses contrast with the recent findings in meerkats (Suricata suricatta), another obligatorily cooperative mongoose with similar group size but wherein reproductive skew is high. Our results suggest that relative contributions by breeders vs non-breeders are not dependent on group size but on the ratio of breeders to carers and the probability that non-breeders will breed in the near future.  相似文献   
87.
Carrion crows Corvus corone corone in northern Spain form complex cooperative groups that contain non-dispersing offspring and immigrants. Reproduction is often shared among group members, with polyandry prevalent over joint egg laying. However, due to incest avoidance or sexual immaturity, reproduction is potentially available only to a fraction of group members (potential breeders), while others do not breed (non-breeders). We combined molecular data with video-recorded observations at nests in order to investigate whether potential breeders and non-breeders adjust their individual effort in nestling feeding respectively to their level of parentage and the relatedness with the chicks. Overall, parents of at least one chick in the brood showed the highest feeding rates. Among potential breeders, genetic mothers and fathers fed chicks at significantly higher rates than individuals with no parentage, but they did not adjust their effort according to the proportion of offspring generated. Current direct fitness benefits are therefore important in determining a high provisioning effort, but crows may lack a mechanism to finely assess their share of parentage. Among non-breeders, males contributed more than females to chick feeding, but we found no significant correlation between feeding rate and relatedness to the nestling. We discuss how the latter result can be reconciled with the fact that kin selection has been shown to be important in shaping the crow cooperative society.Communicated by C. Brown  相似文献   
88.
Optimal investment theory is based on the assumption that the proximate constraint acting on parental investment is resource based. A trade-off between per offspring investment and total investment seems intuitive. Consequently, a parents investment strategy is expected to represent a trade-off between the benefits of investment for current offspring and the costs to future reproduction for parents. In this study, we provide clear evidence that the costs and benefits of maternal provisioning in the dung beetle Onthophagus taurus influence the amount of provisions provided by the mother. Horse dung is typically of a higher nutritional value than cow dung and females were shown to provide 20% less dung to offspring when provisioning with horse dung. By reducing their investment per offspring and exhibiting a clear preference to provision offspring with horse dung, females were able to produce significantly more offspring. Females provisioning with horse dung received greater fitness returns per unit of investment and experienced lower provisioning costs, in terms of the minimum amount of dung required to produce a surviving offspring, than females provisioning with cow dung. Females provisioning in soil of low moisture content were found to have higher tunneling costs than those provisioning in soil of high moisture content, while the fitness returns per unit of investment did not differ. We adopted a marginal value theorem (MVT) approach to calculate the theoretical optimal level of investment for each dung type and for each soil moisture. Predicted levels of provisioning were lower for horse dung than for cow dung and for moist soil than for dry soil. Therefore, the results of this study are in qualitative agreement with MVT predictions and provide empirical support for the proposal that females can adaptively adjust their level of investment in response to resource and/or habitat quality. However, the theoretically predicted optimal investment yielded a poor quantitative fit with our observed levels of investment, with females providing over twice the investment predicted by the MVT approach. We suggest that this difference may reflect either our inability in directly quantifying all the necessary costs and benefits of investment in O. taurus and/or the applicability of the underlying assumptions of MVT.Communicated by D. Gwynne  相似文献   
89.
人工合成麝香的环境污染、生态行为与毒理效应研究进展   总被引:14,自引:0,他引:14  
人工合成麝香作为一种替代型香料被广泛应用于日用化工行业,由于其持续不断地输入环境,其中的一些典型化合物如加乐麝香和吐纳麝香等在水、土壤和大气环境中的浓度日益升高,并且在动物体和人体组织中产生了蓄积作用,其效应相当于持久性有机污染物.因此,人工合成麝香作为一种新型污染物,已成为药物和个人护理品污染物(PPCPs)的重要组成部分.首先对人工合成麝香的种类与应用情况、环境来源和污染水平进行了简要介绍.在此基础上,从人工合成麝香的生物蓄积行为、环境降解行为和生物转化行为等3个方面,对人工合成麝香所具有的持久性有机污染物的行为特征进行了分析;概述了人工合成麝香的环境激素毒性、遗传毒性效应、生理生态毒性、对酶活性的影响以及对微生物毒性效应的研究进展,展示了人工合成麝香所可能产生的不良生态效应.最后,根据目前对人工合成麝香的研究进展,提出了今后有关重点研究内容的建议,为合理评价和降低人工合成麝香的生态风险提供理论基础.  相似文献   
90.
• A hydrophilic resin (GCHM) was facile synthesis and characterized. • Average absolute recovery of GCHM (75.6%) performs better than Oasis® HLB. • Detection limits of method (SPE-UPLC-MS/MS) ranged between 0.03 and 0.6 ng/L. • 22 PPCPs were determined in environmental waters ranging from 0.5 to 1590 ng/L. In this study, a hydrophilic resin named GCHM was fabricated based on poly(N-vinyl pyrrolidone-co-divinylbenzene), characterized, and applied as a solid-phase extraction (SPE) material. Up to 44 pharmaceuticals and personal care products (PPCPs) belonging to 10 classes were recovered in environmental water samples. Different variables affecting extraction, such as adsorbent amount, sample pH, and loading speed, were optimized. Under optimal conditions, the average absolute recovery of 44 PPCPs was 75.6% using GCHM, indicating a better performance than the commercial Oasis® HLB. SPE with home-made hydrophilic polymeric sorbent followed by ultra-performance liquid chromatography and tandem mass spectrometry was validated, and the method achieved good linearity (r2>0.991, for all analytes). In addition, the method detection limits of target compounds ranged from 0.03 to 0.6 ng/L. The developed method was applied to determine PPCPs in 10 environmental water samples taken from the Yangtze River, Huaihe River, and Taihu Lake, 1 groundwater sample from Changzhou in Jiangsu Province, 1 wastewater sample from Xiamen and 2 seawater samples from the Jiulong River in Fujian Province, China. In these samples, 22 compounds were determined at levels ranging from 0.5 to 1590 ng/L.  相似文献   
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